<?php
// #region demo
$link = mysqli_connect('127.0.0.1', 'root', 'root', 'test');

if ($link === false) {
    exit("Link connection failed.");
}

$result = mysqli_query($link, "INSERT INTO `users` (`account`, `password`) VALUES ('Fly', '123456')");

if ($result === true) {
    echo "Inserted";
}
// #endregion demo